Besifloxacin ophthalmic suspension 0.6% (Besivance, Bausch & Lomb) was approved recently by the FDA for the treatment of bacterial conjunctivitis. Besifloxacin suspension is able to fight bacteria that are growing resistant to older anti-infectives.
Approved by the FDA May 29, besifloxacin is said to be the first fluoroquinolone specifically developed for ophthalmic use and the first and only ophthalmic fluoroquinolone with no previous systemic use, according to clinical trial outcomes.
Paul M. Karpecki, OD, an investigator on one of the trials, said this is important because he and his colleagues are becoming increasingly concerned about bacterial resistance to topical anti-infectives.
In one such trial, led by Dr. Karpecki, patients aged 1 to 98 years were dosed three times a day for 5 days. Clinical resolution was achieved in 45% of patients in the besifloxacin suspension 0.6% group, versus 33% of patients in the vehicle-treated group. Those patients treated with the besifloxacin suspension also experienced an eradication rate for bacterial pathogens of 91% versus 60% for the vehicle-treated group.
Researchers found besifloxacin to be effective against many different bacteria, including the Centers for Disease Control and Prevention coryneform group G, Corynebacterium pseudodiphtheriticum, C. striatum, Haemophilus influenzae, Moraxella lacunata, S. aureus, S. epidermidis, S. hominis, S. lugdunensis, Streptococcus mitis group, Streptococcus oralis, Streptococcus pneumoniae, and Streptococcus salivarius.
Dr. Karpecki noted that besifloxacin suspension 0.6% was significantly more effective against MRSA-CR and MRSE-CR than gatifloxacin and moxifloxacin. He said he has encountered more than one case of MRSA resistance in his private practice, now located in Lexington, KY, and has depended on fortified medications to resolve the infection. When fourth-generation fluoroquinolones first were approved several years ago, they were sufficient to stop most infections, he said. Recently, however, he has needed to use fortified antibiotics more frequently.
"We alternated fortified antibiotics (such as tobramycin 13 mg/ml in a contact lens-related keratitis or vancomycin 50 mg/ml in a non-contact lens-related keratitis) with a fluoroquinolone a lot more in the last year because we started to see cases that were not responding to one [fluoroquinolone] or the other," Dr. Karpecki said. "Now, having this new antibiotic, we'll have more confidence in starting our patients on just one fluoroquinolone again. ... To be able to go to a single fluoroquinolone with this kind of potency really will make managing these patients much easier-which will be particularly beneficial in pre and post-surgical cases where an unknown pathogen such as MRSA could develop."